The present invention relates to a slot machine having a plurality of reels each provided with an annular series of various symbols, and more particularly relates to a slot machine in which a plurality of reels are driven by means of pulse motors or stepping motors.
The prior art in this field includes slot machines having a plurality of reels mounted individually rotatably on a common shaft, each reel having an annular series of various symbols such as pictures of a cherry, a bell, a bar, or characters or numerals such as "7" or the like on the peripheries of the respective reels at regular intervals. The reels are caused to rotate simultaneously by manipulation of an actuator handle after inserting coins or tokens in the machine. A plurality of latch means or stop levers associated with respective reels are automatically operated to stop the respective reels after mutually different periods of time predetermined by mechanical timers or upon the actuation of stop buttons associated with the respective reels. Upon the respective reels stopping at random during each game to display various combinations of symbols which are visible through a window provided in a housing of the machine, the machine detects predetermined prize-winning combinations of symbols to cause the pay out of different numbers of coins, tokens or the like.
In these known slot machines, there is the disadvantage that the machine is complicated in construction and/or noisy in operation, since the reels are caused to rotate and to stop in different positions by means of mechanical devices.
Furthermore, these machines have to be provided with means for detecting the stop positions of the respective reels in order to determine whether a predetermined prize-winning combination of symbols is displayed in the window, for the purpose of paying out coins. It is known to provide a mechanical stop-position-detecting device comprising a circular row of contacts corresponding to the number of symbols and brushes or an optical stop position detecting device comprising a circular row of holes bored through a disc rotatable together with the respective reel, corresponding to the number of symbols and photo-couplers, for generating coded signals corresponding to the actual stop positions. In such machines, however, there is the disadvantage that the stop position detecting devices are complicated due to the need to provide a large number of contacts and brushes or photo-electric devices. In the case of the contact-brush arrangement, particularly, there is the great problem that the contact members soon undergo substantial wear and tear and so are poor in durability.